Band-brake.



G. H. BENTON.

BAND BRAKE.

APPLIOATION FILBD- APR. 21, 1909.

Patented Dec. 6,1910.

2 SHEETS-SHEET 1.

WJTNESSES: Z4( M Y W G. H. BENTON.

BAND BRAKE. APPLIUATION FILED 111111.21, 1909.

Patented Dec. 6, 1910.

A TTORNEY.

GILBERT H. BENTON, OF DENVER, COLORADO.

BAND-BRAKE.

ermita.

To all whom it may concern:

Be it known that I, GILBERT H. DEN'roN, a citizen of the United States of America, residing at Denver, in the'county of Denver and State of Colorado, have invented certain new and useful Improvements in Band- Brakes, of which the following is a specitication.

This invention relates to certain new and useful improvements in band-brakes and more particularly to the class of brakes employed to retard the rotatory movement of the winding drum on a hoisting engine, and the principal object of the invention resides in the provision of a system of coperative levers by means of which the band may be drawn around the circumferential brake surface of the drum more firmly and with less expenditure of energy than can be accomplished by a mechanism in which the free end of the band is more directly associated with the operating lever.

A further object of the invention resides in the provision of an operating mechanism so constructed that the brake band associated therewith will, when actuated, engage a greater part of the circumferential surface of the drum, than is ordinarily the case in brakes of this character, and which will thus produce more friction and consequent restraining force. attain the last named object by applying` the power exercised by the above mentioned lever system, to the free end of the band at a point in close proximity to the surface of the drum and to the point of tangency of its opposite extreme portion which, as in the brake bands now in use, extends tangentially to the surface of the drum and is secured at its extreme portion upon a suitable stationary support.

In the accompanying drawings in the various views of which like parts are similarly designated, Figure 1, represents a vertical section taken through the brake drum of a hoisting engine equipped with my improved brake-operating mechanism, Fig. 2, a plan view of the parts illustrated in Fig. 1, Fig. 3, an enlarged, partially sectional view of the means employed to adjust the pitman and lever employed in the construction and Fig. L1, a section taken along the line lr-4 Fig. 3.

Referring to the drawings by numerical reference characters, let the numeral 2 designate the bed-frame of a mine hoisting engine upon which the drum 3 is revolubly supported.

Specification of Letters Patent.

Application led April 21, 1909.

Patented Dec. 6, 1910.

Serial No. 491,357.

The flanged brake-wheel l which forms part of the drum 3, is partly surrounded by the brake band 5, one end, 5, of which projects tangentially to the surface of the wheel and is rigidly secured at a point G to the frame 2. The opposite extremity of the band 5 terminates in close proximity to the circumferential surface of the wheel and to the point of tangency of the xed portion and is provided with a metallic knuckle 7 by means of which it is pivotally secured to the extremity of an outwardly projecting lever 8. The latter is composed of two parallel members extending at opposite sides of the downwardly ranging, tangential portion 5a of the band and these members are connected by means of a bolt and a therewith associated distance sleeve 9 and fulcrunied upon the upper extremities of two parallel bars 10 whose lower ends are pivotally supported upon a bearing 12 mounted upon the bedframe 2.

lThe lever 8 carries at its outer extremity, a centrally bored block 13 provided with trunnions 14 which project loosely through corresponding apertures in the two members of which the lever is composed.

A pitman 15, whose threaded upper portion projects through the bore in the block 13 and is held in its adjusted position by the use of nuts 16, is pivotally connected at its opposite, lower extremity with a crank arm 17, rigidly secured upon a rocker shaft 18 which is revolubly mounted in bearing boxes 26 on the bed frame 2.

A controlling lever 2O is mounted at its lower extremity, upon the rock-shaft 18, and may be held in any one of a plurality of predetermined positions by the engage ment of a spring-held detent 21 with the peripheral teeth of asegment 22 which is secured upon the bed-frame either separate from or as part of one of the journal boxes 18.

The band 5 is preferably composed of two sections which are provided at their juxtaposed-ends, with angle plates 23 which are adjustably connected by means of a bolt 241 and a therewith associated nut 25. This feature of my invention, although not essential, is advantageous in providing an adjustment, which together with the adjustable connection between the pitman 15 and the lever 8, serves to compensate for elongation of the band 5 or to vary the degree of motion of the parts comprised in the lever system,

to suit dierent circumstances and condiwhile its opposite end terminates in close tions.

Having thus described the mechanical construction of the improved brake-mechanism, its operation and the advantages derived therefrom will be readily understood.

lWhen the hoisting engine is in action and the brake band is loose upon the surface of the flanged brake wheel, the operating lever 2O is, approximately, in the position indicated in broken lines in Fig. l of the drawings. To arrest the rotary movement of the drum 3, the operator disengages the detent 2l from the peripheral teeth of the segment 22 and by movement of the lever 2O in the direction of the arrow, causes the shaft 18 to rotate in the boxes 26. The consequent movement of the crank arm 17, is through the instrumentality of the pitman l5, transposed into a motion of the lever' 8 about its fulcrum upon the parallel supports l0, with the result that the free end of the brake-band 5 is drawn upwardly toward the point of tangency of its opposite, fixed portion with the wheel, so as to frictionally embrace the latters circumferential surface.

By reason of the oscillatory motion of the bars 10, in coperation with the movement of the lever 8about its fulcrum, the free end of the brake-band 5 will move in an arc approximately concentric to the brake surface, so that the said end will, during each part of the operation, be in contact with t-he said surface.

While I have shown and described my invention in the best form now known to me, it will be understood that I do not limit myself to the precise construction herein disclosed, since various changes in the form and arrangement of the parts may be availed of within the spirit of my invention.

What I claim and desire to secure by Let- 1. In a band-brake, the combination with an element having a circular brake-surface, of a band partly encircling the same, an end portion of the said band projecting tangentially to the said surface and being fixed at its extremity upon a stationary support,

proximity to the said surface, an arm oscillatory upon a stationary support, a lever fulcrumed upon the free extremity of the latter and connected with the free end of the band, a controlling lever, and a means, for transposing an oscillatory motion of the latter into a movement of the first named lever about its fulcrum.

2. In a bandbrake, the combination with an element having a circular brake-surface, of a band partly encircling the same, an end portion of the said band projecting tangentiall'y to the said surface and being fixed at its extremity upon a stationary support while its opposite end terminates in close proximity to the said surface, an oscillatory support, a lever fulcrumed upon the free extremity of the latter and connected with the free end of the band, a controlling lever, a crank arm operatively associated therewith, and a pitman connecting the latter with the rst named lever.

3. In a band brake the combination with an element having a circular brake-surface, of a band partly encircling the same, an end portion of the said band projecting tangentially to the said surface and being xed at its extremity upon a stationarysupport, while its opposite end terminatesin close proximity to the said surface andr to the point of tangency of the fixed end portion, and a lever one arm of which is pivotally connected with the free end of the band and intersects the said fixed end portion, the said lever having its fulcrum movable in the direction of the brakesurface, whereby when by actuation of the opposite arm of the said lever, the latter is moved about its fulcrum, the free extremity of the said band will be drawn simultaneously t0- ward the point of tangency of its fixed portion and toward the said surface.

In testimony whereof I have afiixed my signature in presence of two witnesses.

GILBERT H. BENTON. Vitnesses M. L. GEARY, Gr. J. RoLLANDn'r. 

